At the headwaters of the Big Blackfoot River, it's difficult to imagine that the waters become, just a little ways downstream, one of the most revered and iconic rivers in the West. The river effectively originates from a 4-inch pipe, above which stands a humming wastewater treatment plant. Above that, hundreds of thousands of yards of toxic mine tailings lie ensconced, tenuously, in an earthen dam.
Today, snow cover conceals the extent of the pollution, but signs of it emerge in exposed ground, reddened by acid mine drainage. Even below the pipe, where the Blackfoot begins in earnest a 132-mile meander to its confluence with the Clark Fork River, the streambed is scarred and discolored. Here, the mystique of the river, so steeped in fly-fishing lore and notions of purity, becomes myth.
Since the early 1940s, the Mike Horse Dam has loomed over the Blackfoot, holding back contaminates from the Mike Horse Mine, part of a mountainous mining district called the Upper Blackfoot Mining Complex (UBMC) some 15 miles upstream of Lincoln. In June 1975, at the peak of the spring runoff, the Mike Horse Dam, itself partly constructed of tailings, blew out, washing 100,000 tons of fine-grain tailings—laced with silver, gold, zinc, lead, cadmium, iron, copper and arsenic—into Beartrap Creek and the upper Blackfoot River, devastating fish and other aquatic life for miles. Shortly thereafter, the mine's owner, American Smelting and Refining Company, LLC (ASARCO), shoddily fortified the dam with more earth and tailings. Ever since, despite the Montana Legislature designating the UBMC a state Superfund site in 1991, the potential for the dam to fail again has weighed heavily over the river, and on the minds of those who love it.
This spring—36 years after the blowout—brings the beginning of the end of the Mike Horse Dam. A $39 million settlement with ASARCO and the Atlantic Richfield Co., which assumed a lease of the property in the '60s, is allowing the state and federal government to finally begin the process of removing the dam and the contaminated tailings behind it, and restoring the historic headwaters of the Blackfoot River. That the dam will be removed at all—as opposed to permanently entombed in place, as ASARCO, as it sank into bankruptcy, had argued for—counts as a major victory for the U.S. Forest Service and Montana Department of Environmental Quality (DEQ), the two agencies leading the restoration effort.
- Photo by Chad Harder
- The Forest Service and Department of Environmental Quality say this piece of ground, known as Section 35, off Highway 279 east of Lincoln, may be the best place to bury the metals-laced tailings contained behind the Mike Horse Dam at the headwaters of the Blackfoot River.
But that victory created a quandary: If the toxic tailings are going to be removed, where should they be moved to? The agencies and Lincoln-area residents have been grappling with the question for more than three years. In the coming weeks, the DEQ and Forest Service will release their analysis of the various options, none of which appear ideal—an understatement as far as some potentially affected neighbors are concerned. Those neighbors charge that the agencies have already chosen a site for the repository, absent public input and corrupted by backroom dealings.
It's not only residents, though, who find themselves watching the restoration of the upper Blackfoot unfold. The river's reach spreads well beyond its banks, to communities all over the state and, thanks to Norman Maclean, across the country.
"This particular project, and its impact, is very far reaching," says Shellie Haaland, a DEQ reclamation specialist who works solely on the UBMC. "It's Great Falls, it's Helena, it's Missoula. It's three large populations of people who have lived and played here for decades, and it is very, very important to a lot of people."
"And it's A River Runs Through It, so there are national implications," adds Amber Kamps, the Lincoln district ranger. "We're hearing from those folks as well."
Haaland and Beth Ihle, a geologist with the Helena National Forest, drive single-lane highways and snow-packed forest roads between Lincoln and Rogers Pass pointing out potential locations for a tailings repository. As the truck passes marshy creek bottoms and winds around mountainsides, it becomes abundantly clear that there are no obvious places for a 30-acre landfill.
"We're in a mountainous environment, let's face it," Ihle says. "Where do cities put their landfills? They don't put them up on slopes like this," her hand at a sharp angle. "Well, this is the environment we have. That's our dilemma, in the end."
What they're looking for, ideally, is flat ground above about 15 feet of clay or limestone. "That's not going to happen," Haaland says. "It's just not. But what we're looking for up here is benched topography, something that will give us something to work with that's not a 35 percent slope."
Even that's hard to find here in these rolling forestlands, where the tailings will likely have to end up. Siting the repository within the Superfund area is advantageous largely because it precludes the need for a landfill permit. As Haaland says, "The whole point of Superfund is to streamline the process." But more practical reasons are at play, namely cost. Costs increase exponentially the farther the tailings are moved. Haaland estimates that the mining complex currently holds between 600,000 and one million cubic yards of toxic waste (about 420,000 cubic yards are impounded in the dam itself). Assuming a single dump truck can carry about 20 cubic yards, that's 40,000 roundtrips from the Mike Horse Dam to a repository, give or take 10,000.
"That's a lot of trucks," Haaland and Ihle say in near unison. And it's the single greatest cost of the project. They say $39 million sounds like a lot of money, but it hardly is for a project that will take a decade to complete. The closer the repository is to the dam, the further that money can be stretched.
Back in 2007, when the Forest Service released its Engineering Evaluation/Cost Analysis, they laid out a simple solution: depositing the tailings in an existing repository created years ago by ASARCO. It's adjacent to Paymaster Creek, just off the forest road that connects the mining complex to Highway 200.
- Photo courtesy of DEQ
- In 1975, the spring runoff breached the Mike Horse Dam, washing 100,000 tons of fine-grain tailings—laced with silver, gold, zinc, lead, cadmium, iron, copper and nickel—into Beartrap Creek and the upper Blackfoot River, devastating fish and other aquatic life for miles. This aerial photo was taken shortly after the blowout.
"Paymaster was chosen because of its proximity to the waste, where it's at right now," Haaland says. "It's the closest, therefore, with the information that we had at the time, it was the most economically viable, feasible solution."
Not anymore. For starters, estimates of the volume of waste within the impoundment have nearly doubled. "And that changes the game," Haaland says. "What would have been a 20-foot impoundment is more like a 50-foot impoundment, just because of [Paymaster's] landform."
Haaland and Ihle pull up to the Paymaster site. It sits up-mountain in a clearing surrounded by dense pine, with an average slope of about 24 percent. But Haaland and Ihle point not to the repository itself, but what sits downhill on the other side of the road—the still-nascent Blackfoot River. The 50- to 80-foot retaining berm Paymaster would require to accommodate the Mike Horse tailings would be built about 50 feet from the river.